The present invention relates to cosmetic stick compositions, i.e., cosmetic solid stick compositions such as deodorant solid stick compositions. More specifically, the present invention relates to cosmetic solid stick compositions containing an alcohol (for example, a monohydric alcohol, such as ethanol, or a polyhydric alcohol, such as propylene glycol) and water, and gelled with a soap (for example, an alkali metal salt of a saturated fatty acid). In particular, the present invention relates to clear cosmetic solid stick compositions with improved clarity, so as to achieve an improved appearance, which retain such improved clarity over an extended period of time, and which have improved pliability while maintaining satisfactory rigidity.
The present invention is especially related to clear, soap-gelled deodorant stick compositions that are clear and maintain such clarity for extended periods of time, and which have improved pliability while maintaining rigidity, the compositions containing a deodorant active material such as a fragrance and/or an antibacterial agent. However, the present invention is not limited to clear, soap-gelled deodorant stick compositions, but has general applicability to other clear sticks. That is, depending on the cosmetic active ingredient incorporated in the stick composition (for example, a deodorant active ingredient, an insect repellant, a sunscreen, an emollient, etc.), the cosmetic stick composition according to the present invention can be a deodorant stick composition, an insect repellant stick, a sunscreen stick, a skin care stick, etc.
It has been desired to provide a soap-gelled, clear cosmetic stick composition, such as a soap-gelled, clear deodorant solid stick composition, which retains clarity over an extended period of time so as to have a long shelf life. Such clear stick compositions have widespread consumer appeal. It has been desired to provide such clear stick composition which maintains clarity for extended periods of time, e.g., prior to being purchased by the consumer and until the product has been used up by the consumer. In particular, it has been desired to provide such a clear stick composition, having a long shelf life, which avoids crystals forming in the stick.
It has also been desired to provide a soap-gelled clear cosmetic stick composition, such as a deodorant solid stick composition, having improved pliability while maintaining satisfactory rigidity of the stick. By improved pliability, we mean that the fracture potential of the cosmetic stick is reduced. Consequently, the consumer is better able to roll the stick product out of the dispensing package without the stick product fracturing, or to remove the cap from the dispensing package without breakage of the stick product. Improved pliability would reduce propensity of product breakage when the dispensing package cap is removed, where the product is stored with the end of the stick protruding from the dispensing package.
U.S. Pat. No. 4,759,924 to Luebbe, et al, the contents of which are incorporated herein by reference in their entirety, discloses transparent, soap-gelled cosmetic stick compositions containing a polyhydric aliphatic alcohol having 2-6 carbon atoms and 2-6 hydroxyl groups; water; a soap gel-forming agent; and a hydro-alcoholic soluble emollient having the formula R(OC.sub.3 H.sub.6).sub.a (OC.sub.2 H.sub.4).sub.b OH, where R is either hydrogen or a hydrocarbon chain having from about 1 to 18 carbon atoms, and a/(a+b).ltoreq.0.5. This patent discloses that the polyhydric alcohol can illustratively be ethylene glycol or propylene glycol, and that mixtures of polyols can be used; and that, illustratively, the soap gel-forming agent can be selectedfrom the sodium, potassium and aluminum salts of saturated or unsaturated fatty acids containing from about 14 to 18 carbon atoms. Preferred soap gel-forming agents include sodium stearate, sodium palmitate, potassium stearate, potassium palmitate, sodium myristate and aluminum monostearate. Illustrative hydro-alcoholic soluble emollients include PPG-5-Ceteth 20, PPG-3-Myreth-3, PEG-20-laurate, PEG-6-32 and Polyoxamer 335.
U.S. Pat. No. 4,759,924 further discloses that the stick composition can include various optional ingredients, including conventional deodorant materials; and that the stick composition (gel stick) can be used by the consumer by rubbing the stick on the area of the body where application is desired. For example, in the case of a deodorant stick for underarm application, the stick is rubbed in the axillary area to apply the deodorant material.
While U.S. Pat. No. 4,759,924 describes a stick composition that is indicated as being transparent, this patent does not disclose maintenance of transparency, or clarity, of the stick over an extended period of time. Moreover, this patent is silent as to the pliability of the formed stick.
U.S. Pat. No. 5,128,123 to Brewster, et al, the contents of which are incorporated herein by reference in their entirety, discloses cosmetic compositions, in the form of sticks, which are clear and mild, containing (in addition to a polyhydric alcohol having from 2-6 carbon atoms and from 2-6 hydroxyl groups, water, and a soap gelling agent) both (a) an alkoxylate copolymer, and (b) a basic amine clarifying agent present in an effective amount to maintain clarity of the stick. The alkoxylate copolymer has a formula [A-CH.sub.2 CH.sub.2 -A].sub.f [(C.sub.2 H.sub.4 O).sub.a (C.sub.3 H.sub.6 O).sub.b (C.sub.2 H.sub.4 O).sub.c (C.sub.3 H.sub.6 O).sub.d ].sub.e [H].sub.g, where A is nitrogen; a, b, c and d are independently selected integers ranging from 0 to 200 with the proviso that the sum of a, b, c and d is at least about 50; e is an integer from 1 to 4; f is an integer from 0 to 1; and g is an integer from 0 to 4. This patent discloses that the copolymer partially replaces soap as a structurant in the stick. This patent further discloses that when f and e are 0 and 1, respectively, the structure described is a poly(ethylene oxide) (propylene oxide) (ethylene oxide) copolymer. This patent further discloses that the clarifying agent is preferably selected from amino alkanols having from 2-6 hydroxyl groups, particularly effective being the propanol amines.
U.S. Pat. No. 5,128,123 also defines what is meant by the term "clear" with respect to the stick composition described therein. Specifically, the term "clear" has its usual dictionary definition; thus, a clear cosmetic stick, like glass, allows for ready viewing of objects behind it. This patent contrasts clear cosmetic sticks with translucent cosmetic sticks, which allow light to pass through but causes the light to be so scattered that it will be impossible to clearly identify objects behind the translucent stick. Thus, in the present art there is a difference between clear, translucent and opaque sticks. This patent goes on to define clear, translucent and opaque sticks based on transmittance of light of wavelengths in the range of 400 to 900 nm through a sample 1 cm thick.
While U.S. Pat. No. 5,128,123 discloses a clear cosmetic stick which is intended to maintain clarity over extended periods of time, this patent does not provide any disclosure concerning pliability of the product.
U.S. Pat. No. 4,822,602 to Sabatelli discloses a cosmetic stick composition including the following components: (a) water-soluble active; (b) dimethicone copolyol; (c) volatile silicone oil; (d) propylene glycol; (e) C.sub.2 -C.sub.4 monohydric alcohol; (f) water; (g) solidifying agent; and (h) coupling agent. The "dimethicone copolyol" is defined in this patent as one or more polyalkylene oxide modified dimethylpolysiloxanes. The solidifying agent can vary depending upon the particular type of cosmetic stick desired (e.g., wax stick; gel stick), and can be a soap-type gel forming agent such as a sodium, potassium and/or aluminum salt of fatty acid containing from about 14 to about 18 carbon atoms.
U.S. Pat. No. 4,822,602 is not disclosed as being a clear cosmetic stick. Moreover, U.S. Pat. No. 4,822,602 is silent as to the pliability of the cosmetic stick produced.
Accordingly, it is still desired to provide a clear cosmetic stick composition, such as a clear deodorant stick composition, which is clear and maintains clarity over extended periods of time, and which provides a stick product having improved pliability while maintaining rigidity of the stick product.